A conventional lifting device is mounted on each of two armrests of a chair so as to adjust a height of each armrest.
The conventional lifting device contains a first movable tube and a second movable tube fitted on the first movable tube, and the second movable tube has a flexible button fixed thereon, the first movable tube has multiple orifices so that after the flexible button is pressed, a flexible projection extends out of or retracts into one of the multiple orifices, hence a height of each of the first movable tube and the second movable tube is adjusted. However, the conventional lifting device is complicated and is assembled troublesomely.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.